The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
During landing of an aircraft, the role of the thrust reverser is to improve the braking capacity of the airplane by reorienting at least part of the thrust generated by the turbojet engine forward. In that phase, the reverser obstructs the gas jet nozzle and orients the jet flow from the engine toward the front of the nacelle, thereby generating a counter-thrust that is added to the braking of the airplane's wheels.
The means used to perform this reorientation of the flow vary depending on the type of reverser. However, in all cases, the structure of a reverser includes moving cowls that can be moved between a deployed position in which they open a passage in the nacelle for the deflected flow on the one hand, and a retracted position in which they close that passage on the other hand. These moving cowls may also perform a deflection function or simply serve to activate other deflection means.
In cascade reversers, for example, the moving cowls slide along rails so that by pulling back during the opening phase, they expose the cascade vanes arranged in the thickness of the nacelle. A link rod system connects the moving cowl to blocking doors, which are deployed inside the discharge channel and block the outlet in direct flow. In reversers with doors, however, each moving cowl pivots so as to block the flow and deflect it, and is therefore active in that reorientation.
More specifically, a thrust reverser device with doors includes one or more doors pivotably mounted so as to be able, under the action of driving means, to tilt between a so-called closed inactive position during so-called direct jet operation of the turbojet engine, in which the doors are part of the downstream section, and a reversed position or open position in which they tilt such that a downstream portion of each door at least partially obstructs the duct of the nacelle and an upstream portion opens a passage in the downstream section to allow the flow of air to be channeled radially in relation to a longitudinal axis of the nacelle.
The pivot angle of the doors is adjusted so as to greatly reduce or even eliminate the thrust force generated by the flow escaping in direct jet, possibly until a counter-thrust is generated while generating a component of the flow deflected in the upstream direction of the nacelle.
For a general description of thrust reversers with doors, see documents FR 1 482 538, FR 2 030 034, or U.S. Pat. No. 3,605,411.
To be able to improve the reorientation of the flow of air in a direction tending as much as possible toward a longitudinal direction of the nacelle, the doors are also equipped with end inserts, also called deflectors, forming a return upstream of the door substantially perpendicular thereto. Thus, when the door is in the thrust reversal position, the insert is oriented in a substantially longitudinal direction of the nacelle and forces the flow of air in that direction.
This insert is mounted to be retractable into the thickness of the door so as to prevent the insert from penetrating the circulation tunnel of the flow of air and blocking the flow of air circulating in direct jet in the closed position.
Improvements in the effectiveness of thrust reversers are continuously sought so as to be able to simplify the operation thereof and consequently increase their reliability and performance and decrease their mass.